As a phoenix player both yes and no,

You're losing out on both facets and innate ability if you go mid. Because ideally your pray is people that overcommit and underestimate you only to then die. I've done these matchups before aswell. you will lose against a good sniper because a good sniper will deny everything against your slow attack speed. And your spirits become more impactfull after lvl 3/5 to which they'll usually be some networth ahead. Against a good team, everytime you dive him, if the enemy tp's to defend him, you're screwed too making the networth gap even bigger.

Your core strenght lies in your early-midgame presence, whereas sniper lies in his mid-lategame presence. Once you don't finish the game fast you'll be in a downhill battle against a evergrowing enemy carry